TCP (Transmission Control Protocol), the most widespread IP (Internet Protocol) communications technology, has the following two functions for retransmission control. These are a fast retransmit function (Fast Retransmit) in which the transmitting side retransmits when three retransmission requests relating to packet loss are received from the receiving side, and a SACK (Selective ACK) option function that contains packet reception data in the acknowledgement information (ACK).
[Non-patent Literature 1] TCP: RFC793 (http://www.faqs.org/rfcs/rfc2001.html)
[Non-patent Literature 2] Fast Retransmit: RFC2001 (http://www.faqs.org/rfcs/rfc2001.html)
[Non-patent Literature 3] SACK: RFC2018 (http://www.faqs.org/rfcs/rfc2018.html)